The present invention relates to a process for the production of an N,N-dialkylallylamine polymer and an N,N-dialkylallylamine polymer. More specifically, it relates to a process for efficiently and industrially advantageously producing an N,N-dialkylallylamine polymer or an addition salt thereof, a copolymer of N,N-dialkylallylamine and a monoallylamine or an addition salt thereof, and a copolymer of N,N-dialkylallylamine and a diallylamine or an addition salt thereof, which are useful in the field of fine chemicals, and also to an N,N-dialkylallylamine polymer or an addition salt thereof, a copolymer of N,N-dialkylallylamine and a monoallylamine or an addition salt thereof, and a copolymer of N,N-dialkylallylamine and a diallylamine or an addition salt thereof.
A polyallylamine (allylamine polymer) is a linear olefinic polymer containing primary amino groups in side chains, and it is a cationic polymer which is well soluble in water and positively charged in water. A polyallylamine has characteristic reactive polymer structure and properties and is therefore used in remarkably wide fields of dye fixing agents for reactive dyes, dye fixing agents for direct dyes, additives to inkjet recording paper, and the like. Concerning a method of producing the polyallylamine, there is known a method in which an inorganic acid salt of a monoallylamine is polymerized in water or a polar solvent in the presence of a radical polymerization initiator containing an azo group.
An N,N-dialkylallylamine polymer or an addition salt thereof is considered to be a very interesting practical polymer when compared with a polyallylamine. As described in Comparative Example 12 on page 9 of JP-B-2-14364, however, polymerization of a monomer such as N,N-dimethylallylamine in the presence of a radical polymerization initiator gives only a trace amount (yield 5%) of a polymer, and the monomer undergoes almost no polymerization. No reports have so far said that an N,N-dialkylallylamine polymer is obtained by polymerization at a high polymerization rate.
As a method of producing an N,N-dialkylallylamine polymer, there is therefore known only a method in which an N,N-dialkylallylamine polymer or an addition salt thereof is produced from a certain polymer by chemically replacing substituents of side chains of the polymer. As one method included in the above method, there is known a method in which poly(N,N-dialkylacrylamide) such as poly(N,N-dimethylacrylamide) is reacted with sodium.bis(2-methoxyethoxy)aluminum hydride to produce N,N-dialkylallylamine polymer (U.S. Pat. No. 4,053,512). However, the above method has a problem that industrial production of the end polymer is difficult since the reaction is carried out under anhydrous conditions. As another method, there is known a method in which formic acid and formaldehyde are allowed to react with a polyallylamine to produce an N,N-dialkylallylamine polymer (JP-A-60-108405). Since, however, this method requires two steps for obtaining the end product from a monoallylamine as a starting material, it is not thought to be a satisfactory method.
As described above, it is thought that N,N-dialkylallylamine per se does not easily undergo polymerization, and under the present circumstances, nothing has been reported concerning the successful production of a copolymer from N,N-dialkylallylamine and a monoallylamine or a copolymer from N,N-dialkylallylamine and diallylamine by polymerization.
As a consequence, although N,N-dialkylallylamine, monoallylamines and diallylamines are industrially produced, neither a copolymer of N,N-dialkylallylamine and monoallylamine nor a copolymer of N,N-dialkylallylamine and diallylamine is industrially produced at present.
Meanwhile, as a printer, a dot impact printer, a laser printer, a thermal printer, an inkjet printer, etc., are known. Of these, an inkjet printer is widely used in recent years due to characteristic features such as fast printing with a low noise, a low printing cost, downsizing and weight-decreasing feasibility based on a simple mechanism, an easiness in multi-color printing and image size increasing, non-necessity of development and fixing and high adaptability of a record pattern.
In the above inkjet printer, conventionally, recording is carried out by an inkjet recording method in which an ink blob is generated and ejected by an electrostatic suction method, an air compression method, a method using electric deformation of a piezoelectric element or a method using a pressure caused by heat-blowing, and further, the ink blob is allowed to adhere to a recording paper. As an ink for use with the above recording method, generally, there is used a water-based ink prepared by dissolving or dispersing a colorant such as a dye or a pigment in water, a water-soluble organic solvent or a mixture of these.
In recent years, inkjet recording is required to satisfy water resistance on an ordinary paper, and as a water-based ink composition for attaining the above requirement, combinations of polyethyleneimine and polyamines mainly including modified products thereof with dyes have been studied in various ways.
However, the above polyamines have defects that the water resistance thereof is insufficient, that the shelf life thereof is poor and that the dyes that can be selected are limited.
On the other hand, attempts have been made to use an allylamine polymer as a water-resistance-imparting agent in an ink composition. In this case, however, there are required complicated procedures of reacting an allylamine hydrochloride polymer with a dye (dye containing acid salt such as sulfonic acid salt) to prepare a dye containing an allylamine polymer as a counter cation and removing an inorganic salt, etc., by isolating it as a solid before use, as is described in JP-A-63-33484. Further, for avoiding the above complicated procedures, an allylamine polymer is taken as a free polymer in advance, and further, an inorganic salt, etc., are removed. Even in this case, when the allylamine polymer is used in an ink, the ink is liable to cause aggregation, etc., which causes a problem in practical use.
Under the above circumstances, it is a first object of the present invention to provide a process for industrially advantageously producing an N,N-dialkylallylamine polymer and a copolymer of N,N-dialkylallylamine and other allylamine at high yields, which are useful for various uses in the field of fine chemicals and particularly useful as a water-resistance-imparting agent for an inkjet ink.
It is a second object of the present invention to provide an N,N-dialkylallylamine polymer and a copolymer of N,N-dialkylallylamine and other allylamine, which are useful in the above field.
The present inventors have made diligent studies to achieve the above objects, and as a result have found that the first object can be achieved by polymerizing an addition salt of N,N-dialkylallylamine, or copolymerizing an addition salt of N,N-dialkylallylamine and an addition salt of a monoallylamine or an addition salt of a diallyamine, in the presence of a specific radical polymerization initiator, or by further treating a polymerization solution thereof in a specific method and then subjecting the polymerization product to an ion exchange membrane electrodialysis.
It has been further found that the above second object is achieved by an N,N-dialkylallylamine polymer having a weight average molecular weight in a specific range and an ignition residue content equivalent to, or smaller than, a specific value, a copolymer of N,N-dialkylallylamine and monoallylamine or N-alkylmonoallylamine or an addition salt thereof, or a copolymer of N,N-dialkylallylamine and diallylamine or N-substituted diallylamine or an addition salt thereof.
The present invention has been completed on the basis of the above findings.
That is, the present invention provides;
(1) a process for the production of an N,N-dialkylallylamine polymer having a recurring unit of the general formula (II), 
xe2x80x83wherein each of R1 and R2 is independently an alkyl group having 1 to 4 carbon atoms, or an addition salt thereof, which comprises polymerizing an addition salt of an N,N-dialkylallylamine of the general formula (I), 
xe2x80x83wherein R1 and R2 are as defined above, in an aqueous solvent in the presence of 2 to 100 mol %, based thereon, of a radical initiator having a molecule containing an azo group or a persulfate radical initiator, and optionally neutralizing a polymerization solution (to be referred to as xe2x80x9cProduction Process 1xe2x80x9d hereinafter),
(2) a process for the production of an N,N-dialkylallylamine polymer having a recurring unit of the above general formula (II) or an addition salt thereof, which comprises polymerizing an addition salt of an N,N-dialkylallylamine of the above general formula (I) in an aqueous solvent in the presence of 2 to 100 mol %, based thereon, of a radical initiator having a molecule containing an azo group or a persulfate radical initiator, then, neutralizing a polymerization solution to bring a formed polymer into a free state, further, distilling off a residual monomer under reduced pressure, then, subjecting a remaining polymerization solution to an ion exchange membrane electrodialysis, and optionally carrying out acid treatment (to be referred to as xe2x80x9cproduction process 2xe2x80x9d hereinafter),
(3) a process for the production of a copolymer of N,N-dialkylallylamine and monoallylamine, the copolymer having recurring units of the general formula (IV), 
xe2x80x83wherein R3 is a hydrogen atom or an alkyl group having 1 to 4 carbon atoms, and the above general formula (II), or an addition salt thereof, which comprises copolymerizing an addition salt of a monoallylamine of the general formula (III), 
xe2x80x83wherein R3 is as defined above, and an addition salt of an N,N-dialkylallylamine of the above general formula (I) in an aqueous solvent in the presence of a radical initiator having a molecule containing an azo group or a persulfate radical initiator, and optionally neutralizing a polymerization solution (to be referred to as Production Process 3xe2x80x9d hereinafter),
(4) a process for the production of a copolymer of N,N-dialkylallylamine and monoallylamine, the copolymer having recurring units of the above general formulae (IV) and (II), or an addition salt thereof, which comprises copolymerizing an addition salt of a monoallylamine of the above general formula (III) and an addition salt of N,N-dialkylallylamine of the above general formula (I) in an aqueous solvent in the presence of a radical initiator having a molecule containing an azo group or a persulfate radical initiator, then, neutralizing a polymerization solution to bring a formed copolymer into a free state, further, distilling off a remaining monomer under reduced pressure, subjecting the polymerization solution to an ion exchange membrane electrodialysis, and optionally carrying out acid treatment (to be referred to as xe2x80x9cProduction Process 4xe2x80x9d hereinafter),
(5) a process for the production of a copolymer of N,N-dialkylallylamine and N-substituted or non-substituted diallylamine, or an addition salt thereof, which comprises copolymerizing an addition salt of an N,N-dialkylallylamine of the above general formula (I) and an addition salt of an N-substituted or non-substituted diallylamine in an aqueous solvent in the presence of a radical initiator having a molecule containing an azo group or a persulfate radical initiator, and optionally neutralizing a polymerization solution (to be referred to as xe2x80x9cProduction Process 5xe2x80x9d hereinafter),
(6) a process for the production of a copolymer of N,N-dialkylallylamine and N-substituted or non-substituted diallylamine, or an addition salt thereof, which comprises copolymerizing an addition salt of an N,N-dialkylallylamine of the above general formula (I) and an addition salt of an N-substituted or non-substituted diallylamine in an aqueous solvent in the presence of a radical initiator having a molecule containing an azo group or a persulfate radical initiator, neutralizing a polymerization solution to bring a formed copolymer into a free state, further, distilling off a residual monomer under reduced pressure, then, subjecting the polymerization solution to an ion exchange membrane electrodialysis, and optionally carrying out acid treatment (to be referred to as xe2x80x9cProduction Process 6xe2x80x9d hereinafter),
(7) an N,N-dialkylallylamine polymer having a recurring unit of the above general formula (II), having a weight average molecular weight, measured by gel permeation chromatography using polyethylene oxide as a reference, of 250 to 3,000 and having an ignition residue content of 5% by weight or less (to be referred to as xe2x80x9cPolymer 1xe2x80x9d hereinafter),
(8) a copolymer of N,N-dialkylallylamine and monoallylamine, which copolymer has recurring units of the above general formulae (IV) and (II), or an addition salt thereof (to be referred to as xe2x80x9cPolymer 2 or addition salt thereofxe2x80x9d hereinafter), and
(9) a copolymer of N,N-dialkylallylamine of the above general formula (I) and N-substituted or non-substituted diallylamine, or an addition salt thereof (to be referred to as xe2x80x9cPolymer 3 or addition salt thereofxe2x80x9d hereinafter).